https://cyberleninka.org/article/n/567486.pdf

A review on polycyclic aromatic hydrocarbons: Source, environmental impact, effect on human health and remediation

One of our era's greatest scourges is air pollution, on account not only of its impact on climate change but also its impact on public and individual health due to increasing morbidity and mortality. There are many pollutants that are major factors in disease in humans. Among them, Particulate Matter (PM), particles of variable but very small diameter, penetrate the respiratory system via inhalation, causing respiratory and cardiovascular diseases, reproductive and central nervous system dysfunctions, and cancer. Despite the fact that ozone in the stratosphere plays a protective role against ultraviolet irradiation, it is harmful when in high concentration at ground level, also affecting the respiratory and cardiovascular system. Furthermore, nitrogen oxide, sulfur dioxide, Volatile Organic Compounds (VOCs), dioxins, and polycyclic aromatic hydrocarbons (PAHs) are all considered air pollutants that are harmful to humans. Carbon monoxide can even provoke direct poisoning when breathed in at high levels. Heavy metals such as lead, when absorbed into the human body, can lead to direct poisoning or chronic intoxication, depending on exposure. Diseases occurring from the aforementioned substances include principally respiratory problems such as Chronic Obstructive Pulmonary Disease (COPD), asthma, bronchiolitis, and also lung cancer, cardiovascular events, central nervous system dysfunctions, and cutaneous diseases. Last but not least, climate change resulting from environmental pollution affects the geographical distribution of many infectious diseases, as do natural disasters. The only way to tackle this problem is through public awareness coupled with a multidisciplinary approach by scientific experts; national and international organizations must address the emergence of this threat and propose sustainable solutions.

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Environmental and Health Impacts of Air Pollution: A Review.

Polycyclic aromatic hydrocarbons (PAHs) include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. The increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed towards removing PAHs from the environment. PAHs may undergo adsorption, volatilization, photolysis, and chemical oxidation, although transformation by microorganisms is the major neutralization process of PAH-contaminated sites in an ecologically accepted manner. Microbial degradation of PAHs depends on various environmental conditions, such as nutrients, number and kind of the microorganisms, nature as well as chemical property of the PAH being degraded. A wide variety of bacterial, fungal and algal species have the potential to degrade/transform PAHs, among which bacteria and fungi mediated degradation has been studied most extensively. In last few decades microbial community analysis, biochemical pathway for PAHs degradation, gene organization, enzyme system, genetic regulation for PAH degradation have been explored in great detail. Although, xenobiotic-degrading microorganisms have incredible potential to restore contaminated environments inexpensively yet effectively, but new advancements are required to make such microbes effective and more powerful in removing those compounds, which were once thought to be recalcitrant. Recent analytical chemistry and genetic engineering tools might help to improve the efficiency of degradation of PAHs by microorganisms, and minimize uncertainties of successful bioremediation. However, appropriate implementation of the potential of naturally occurring microorganisms for field bioremediation could be considerably enhanced by optimizing certain factors such as bioavailability, adsorption and mass transfer of PAHs. The main purpose of this review is to provide an overview of current knowledge of bacteria, halophilic archaea, fungi and algae mediated degradation/transformation of PAHs. In addition, factors affecting PAHs degradation in the environment, recent advancement in genetic, genomic, proteomic and metabolomic techniques are also highlighted with an aim to facilitate the development of a new insight into the bioremediation of PAH in the environment.

/pdf/current-state-of-knowledge-in-microbial-degradation-of-480ex77r3r.pdf

Current State of Knowledge in Microbial Degradation of Polycyclic Aromatic Hydrocarbons (PAHs): A Review

Solid waste issue: Sources, composition, disposal, recycling, and valorization

Removal of heavy metal from industrial wastewater using modified activated coconut shell carbon

Over the past few years, concerns regarding water scarcity and pollution have become more prominent. In many regions, water supply management requires support. This study aimed to determine the effect of greywater on vegetative parameters and chemical content on the yucca plant by using pots studies under greywater stress. This study was carried out in pilot plant of the experimental area, National Research Centre, Dokki, Cairo, Egypt, during the two successive seasons of 2021-2022. Yucca plants were irrigated with greywater at different dilutions by tap fresh water at the following percentage of greywater: 50%:50% (50%greywater,50% tap water); 67%: 33% (67% greywater, 33% tap water); 75%:25% (75% greywater, 25% tap water);100% (100% greywater, 0% tap water) while the control samples were irrigated with tap water only. It was found that irrigation of yucca plant with raw grey wastewater recorded the highest values in the proline content, protein and chlorophyll a, b in the plants, while all the vegetative parameters were decreased. By irrigation with 75:25 greywater (i.e., 75 % greywater: 25% freshwater), higher values in cell carbohydrates content were recorded compared to the control (i.e.,100% tap water) and other treatments. On the other hand, irrigation with 67% greywater recorded the highest values in vegetative parameters, followed by irrigation with 75% greywater in comparison with the control one (tap water). From this study, it was concluded that long-term irrigation with greywater exhibited a beneficiary effect on Yucca plant.

Hussein I. Abdel-Shafy

Papers

Reuse of Greywater in Yucca plant irrigation under Phytoremediation stress condition